An internist's view," Dr. David Lewis says this idea has played a "paramount" role in classifying sifying diseases: "If the etiology and/or course of the disease appears to be primarily under the control of an individual, then it is thought to be a moral problem. If, on the other hand, the etiology and/or course of the condition is primarily beyond the control or intention of the individual, it is more acceptable to call that condition a disease." Lewis is not, it seems, defending this view but making an observation regarding how people think about the causes of human behavior and the implications of these ideas for classifying disorders. The view is problematic atic when applied to voluntary behavior. As science has learned more about behavior, it has become increasingly clear that the causes that matter ter are often well beyond anyone's control. We have learned that factors such as as genes, hormones, neurotransmitters, cohort, and gender play a large role in voluntary behavior. Now couple the scientific findings with the assumption that human disorders are subject to two different types of causal relations: those that one is able to control and those that one cannot not control. The implication is that as we learn more about a disorder, the more likely it is to be thought of as a disease. For instance, as we learn more, the causes become more remote, and if they are remote, then they are not under one's control, and hence the disorder can be classified as a disease. Lewis's observations help explain why support for the disease interpretation terpretation has increased over time. They predict that as other behavioral ioral disorders are better understood, the tendency to think of them as diseases eases will also increase. Put more generally, the idea that there are causes under one's control and causes beyond one's control ends up defining voluntary behavior as behavior that is not understood.
References
Heyman, Gene M. 2010. Addiction: A disorder of choice. 1st Harvard University Press paperback ed. Cambridge, Mass. Harvard University Press.